News comes from strange sources, as evidenced by news of Treyarch's upcoming Call of Duty 7, following the successful CoD: World at War and taking after Infinity Ward's Modern Warfare 2.

We learn that the next Call of Duty is already being developed by Treyarch through an employee's profile on LinkedIn, a business-oriented social networking site.  Senior animator David Kim stated in his profile:

I am currently on my second title as a senior animator in the games industry with Activision / Treyarch on Call Of Duty 7. Previous to that I specialized as a previsualization artist for various productions.

Thanks for the heads up, David. even if it was unintentional.  There's still no word on whether this is going to be another World War II shooter, with rumors of a Vietnam-based setting still lingering.